3751821 has 12 divisors (see below), whose sum is σ = 5439772. Its totient is φ = 2491776.

The previous prime is 3751819. The next prime is 3751823. The reversal of 3751821 is 1281573.

It is an interprime number because it is at equal distance from previous prime (3751819) and next prime (3751823).

It can be written as a sum of positive squares in 2 ways, for example, as 1929321 + 1822500 = 1389^2 + 1350^2 .

It is not a de Polignac number, because 3751821 - 2¹ = 3751819 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3751823) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2415 + ... + 3651.

Almost surely, 2^3751821 is an apocalyptic number.

It is an amenable number.

3751821 is a deficient number, since it is larger than the sum of its proper divisors (1687951).

3751821 is a wasteful number, since it uses less digits than its factorization.

3751821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1580 (or 1577 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 3751821 is about 1936.9617962159. The cubic root of 3751821 is about 155.3867690966.

The spelling of 3751821 in words is "three million, seven hundred fifty-one thousand, eight hundred twenty-one".